Energetic evaluation of a solar tunnel dryer for fruits

Abstract

The dehydration process allows agricultural products to be handled in post-harvest seasons, managing to preserve them for longer without causing significant changes in the properties of the product. This study focuses on conducting the energetic evaluation of a solar tunnel dryer for fruits by natural convection, which is located in the village of Las Mangas, municipality of Santa Rosa de Cabal, Risaralda, for the drying processes of banana and tomatoes as foods that registers high rates of crop and production in the area. Then, identified in the first place the constructive characteristics of the device, it was continued to effectuate the operational evaluation that consisted in the study of the dryer applying heat transfer concepts to the collector chamber, as well as energy and mass balance to the drying process. Thus, this analysis allowed to quantify the thermal performance  about 30%, the efficiency during the dehydration process  with averages of 11.2%, 14.6% and 18.3% for the cases analyzed: without load, with banana and tomato respectively and the overall performance  of the system, with averages of 30.5%, 33.2% and 41.2% for the same cases respectively. Some recommendations to improve the dehydrator design and its performance are suggested in this work.